Christian Horner says Red Bull must improve in order to attempt to defend its world championships in 2013.

Sebastian Vettel's drivers' title combined with Red Bull's constructors' championship this year means that the team has won both titles for three consecutive seasons. However, Horner says the team can't afford to relax if it wants to be in a position to defend those championships at the start of next season and must make sure it is stronger than this year.

"Inevitably focus shifts towards 2013," Horner said. "What I can say is we've got a great foundation, we've got a great basis; even if we took this car to the first race next year it would be a good starting point. But Formula One doesn't stand still and we have to evolve, we have to improve, and everybody in the team knows that. As we have improved over the last three years we'll be looking to do the same next year."

One area Horner highlighted as Red Bull having improved on in 2012 was in its mental strength as it dealt with playing catch-up during the middle of the season.

"It gets harder, it never gets easier. This year for sure was the hardest of the three where I think we've had to show true strength of character of the team to fight our way back in to the drivers' championship particularly and also the constructors' as well."